Conventionally, an art of a vehicle is well known which can steer four wheels independently. As such an art of a vehicle, a vehicle described in the Patent Literature 1 is known.
The vehicle described in the Patent Literature 1 has a mode selection means selecting one of a normal mode, a parallel traveling mode and a rotation mode and a direction selection means selecting a traveling direction.
When the mode selection means selects the normal mode, only front wheels of the vehicle are steered by steering operation.
When the mode selection means selects the rotation mode, the front wheels are steered so as to make the front sides thereof close to each other and rear wheels are steered so as to separate the front sides thereof. In this state, by driving each wheel to a predetermined direction, the vehicle can turn centering on a predetermined turning center.
When the mode selection means selects the parallel traveling mode, the four wheels of the vehicle are steered to a direction selected by a direction selection means. Therefore, the vehicle can travel parallel to the selected direction.
However, at the parallel traveling mode, the vehicle described in the Patent Literature 1 can travel parallel to only the predetermined direction (for example, 8 directions) and cannot travel parallel to the other optional direction. For moving parallel to the desired direction, the vehicle must repeat the parallel traveling to the predetermined direction alternately.
Patent Literature 1: the Japanese Patent Laid Open Gazette 2008-13045